it's just something you say to mean, "Let's not burn each other's houses down or boil each others' rabbits, OK?"
okay you made me laugh. hard.
you may have to pull out the serious ammo... "deaf, dumb and blind" i call it. he's approaching you for a hug after a meeting? turn away and put your attention on someone or something else. you do not see him. he's calling on the phone? don't answer. he's somehow corralled you and is asking you to lunch or to gab about his mother? -- you have suddenly been struck dumb and don't say a word.
he is a boundariless person. you have to enforce all of them because he has none. it's not mean. it's self preservation. who cares if somebody notices you don't hug him? first of all i bet they won't. second, i bet even HE won't get it ... at first. but he will eventually and that's all that matters.
and yes, as has been suggested, it's a good idea to enlist the support of your group.
good luck. :hugs: